Prophylaxis for vomiting by children after tonsillectomy: ondansetron compared with perphenazine

We have compared the effects of ondansetron and perphenazine on vomiting after tonsillectomy in 216 healthy children, aged 2-12 yr. The study was randomized, stratified, blocked and double blind. Anaesthesia was induced with propofol i.v. or by inhalation of halothane and nitrous oxide. Ondansetron 150 micrograms kg-1 or perphenazine 70 micrograms kg-1 was administered i.v. after induction of anaesthesia in a double-blind manner. Perioperative management of emesis, pain, fluids and patients discharge were standardized. Ondansetron and perphenazine had similar effects on postoperative vomiting (44% vs 41%; ondansetron vs perphenazine P = 0.77). By logistic regression analysis, the only significant predictor of postoperative vomiting was sex, that is males had a greater incidence of vomiting (49% vs 35%; P = 0.016). In-hospital vomiting was associated with a prolongation of stay in the day-care surgical unit of 7 min per episode of vomiting (P = 0.015). We conclude that ondansetron and perphenazine had similar effects on vomiting in children after tonsillectomy in a day-case setting.

Low-dose ondansetron with dexamethasone more effectively decreases vomiting after strabismus surgery in children than does high-dose ondansetron

BACKGROUND

Ondansetron and dexamethasone have been observed to decrease the incidence of vomiting by children after general anesthesia. This study compared the effect of high-dose (150 microg/kg) ondansetron with low-dose (50 microg/kg) ondansetron plus 150 microg/kg dexamethasone on the incidence of vomiting after strabismus in children.

METHODS

This study had a double-blind, blocked, stratified, randomized design. With parental consent and Hospital Ethics Committee approval, healthy children aged 2-14 yr who were undergoing elective strabismus surgery were studied. Anesthesia was induced intravenously with propofol or by inhalation with halothane and nitrous oxide. Patients in the high-dose group were given placebo plus 150 microg/kg (maximum dose, 8 mg) of ondansetron intravenously, whereas patients in the low-dose group were given 150 microg/kg dexamethasone (maximum dose, 8 mg) and 50 microg/kg ondansetron intravenously in a double-blind manner. Anesthesia was maintained with halothane and nitrous oxide. All incidences of vomiting occurring as long as 24 h after anesthesia were recorded.

RESULTS

Three of the 200 patients enrolled in the study were excluded from data analysis. The groups were similar with respect to demographic data and potential confounding variables. Patients vomited from 0-12 times. The low-dose ondansetron plus dexamethasone group had a lower incidence of vomiting, 9% (95% CI = 4-17%) versus 28% (95% CI = 20-38%; P < 0.001). Only 1% of the patients in the low-dose ondansetron plus dexamethasone group vomited while in the hospital.

CONCLUSIONS

Low-dose ondansetron plus dexamethasone is an effective prophylactic antiemetic combination for children undergoing strabismus surgery.

Vomiting after strabismus surgery in children: ondansetron vs propofol

PURPOSE

To compare the antiemetic efficacy and costs associated with two anaesthetic regimens in children undergoing strabismus surgery. One regimen contained halothane, nitrous oxide and ondansetron, while the other contained propofol and nitrous oxide.

METHODS

Three hundred children aged 2-14 yr undergoing strabismus surgery were enrolled into this single-blind, randomized, stratified, blocked study with a balanced design. Anaesthesia was induced by inhalation with halothane/N2O/O2 (Group O) or with 2.5-3.5 mg.kg-1 propofol + 0.5 mg.kg-1 lidocaine i.v. (Group P). Group O patients were administered 0.15 mg.kg-1 ondansetron (maximum dose 8 mg) i.v. and all patients received atropine 20 micrograms.kg-1 i.v. immediately after induction of anaesthesia. Anaesthesia was maintained with N2O and halothane (Group O) or N2O and propofol (Group P). Patients were followed for 24 hr after their operation primarily to assess the incidence of postoperative vomiting. For each case, the costs of the anaesthetic drugs administered and their associated intravenous administration tubing were determined. Drug costs were those prevailing at the study site at the time of the investigation. Fixed costs, such as the cost of the anaesthetic equipment were not assessed.

RESULTS

Groups were similar with respect to demographic data. The incidence of vomiting in both groups was 11% while in-hospital and 23% after discharge. Each episode of in-hospital vomiting prolonged discharge by 17 +/- 4 min, P < 0.001. Mean cost per case for anaesthetic drugs was less in Group O, 18 +/- 8 vs 21 +/- 10, CDN$, mean +/- SD, P < 0.01.

CONCLUSION

The two methods of antiemetic prophylaxis were equally effective. Propofol-based anaesthesia was more expensive.

Prophylactic antiemetics in children undergoing tonsillectomy: high-dose vs low-dose ondansetron

This randomized, double-blind study assessed the impact of two different doses of intraoperative ondansetron on vomiting following tonsillectomy in 240 preadolescent children in a day care surgical setting. After anaesthesia was established by inhalation with N2O/ halothane or intravenously with propofol, the subjects were administered the study drug (50 or 150 micrograms.kg-1 ondansetron, maximum dose 8 mg). Anaesthesia was maintained with N2O/ halothane. The greater dose of ondansetron (150 micrograms.kg-1) had a lower incidence (36% vs 52%) of postoperative vomiting (P = 0.01). In-hospital emesis was not a problem with only 14% of the subjects vomiting. Eight patients sought medical attention for vomiting after discharge from hospital. In-conclusion, 150 micrograms.kg-1 ondansetron is a more effective prophylactic antiemetic than 50 micrograms.kg-1 ondansetron among children undergoing elective tonsillectomy.

Preoperative ketorolac increases bleeding after tonsillectomy in children

PURPOSE

To compare the incidence of vomiting following codeine or ketorolac for tonsillectomy in children.

METHODS

We had planned to enrol 240 patients, aged 2-12 yr undergoing elective tonsillectomy into a randomized, single-blind study in University Children's Hospital. The study was terminated, after 64 patients because interim analysis of the data by a blinded non-study scientist concluded that the patients were at undue risk of excessive perioperative bleeding. After induction of anaesthesia by inhalation with N2O/halothane or with propofol 2.5-3.5 mg.kg-1 i.v., the children were administered 150 micrograms.kg-1 ondansetron and 50 micrograms.kg-1 midazolam. Maintenance of anaesthesia was with N2O and halothane in O2. Subjects were administered either 1.5 mg.kg-1 codeine im or 1 mg.kg-1 ketorolac i.v. before the commencement of surgery. Intraoperative blood loss was measured with a Baxter Medi-Vac Universal Critical Measurement Unit. Postoperative management of vomiting and pain was standardized. Vomiting was recorded for 24 hr after anaesthesia. Data were compared with ANOVA, Chi-Square analysis and Fisher Exact Test.

RESULTS

Thirty-five subjects received ketorolac. Demographic data were similar. The incidence of vomiting during the postoperative period was 31% in the codeine-group and 40% in the ketorolac-group. Intraoperative blood losses was 1.3 +/- 0.8 ml.kg-1 after codeine and 2.2 +/- 1.9 ml.kg-1 after ketorolac (mean +/- SD) P < 0.05. Five ketorolac-treated patients had bleeding which led to unscheduled admission to hospital, P < 0.05, Exact Test.

CONCLUSION

Preoperative ketorolac increases perioperative bleeding among children undergoing tonsillectomy without beneficial effects.

Ondansetron is a better prophylactic antiemetic than droperidol for tonsillectomy in children

Both intravenous ondansetron (OND) and droperidol (DROP) have been observed to reduce vomiting after tonsillectomy in children. This randomized, double-blind investigation compared the effect of OND and DROP on vomiting after outpatient tonsillectomy in 276 healthy children age 2-12 yr. All subjects received a standardized anaesthetic, which consisted of induction with either propofol or halothane/N2O, vecuronium 0.1 mg x kg(-1) on an as needed basis, maintenance with halothane/N2O, midazolam and codeine, and reversal of neuromuscular blockade with neostigmine and atropine on an as needed basis. Subjects were given either OND 150 micrograms x kg(-1) or DROP 50 micrograms x kg(-1)iv after induction of anaesthesia. Rescue antiemetics in the hospital were administered to patients who vomited X 2 and X 4, respectively. Postoperative pain was treated with morphine, codeine and/or acetaminophen. For 24 hr following surgery, emesis was recorded by nursing staff while subjects were in the hospital, and by parents following discharge from hospital. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. The frequency of in-hospital emesis was 16% in the OND-patients and 30% in the DROP-group, P <0.05. The OND-subjects required fewer rescue antiemetics, 5% vs 13%, P <0.05. The overall incidence of emesis was 45% in the OND-group and 57% in the DROP-group, P <0.05. In conclusion, ondansetron was a superior prophylactic antiemetic for tonsillectomy in children when compared to droperidol.

Nitrous oxide does not increase vomiting in children after myringotomy

The aim of this study was to establish whether nitrous oxide has a clinically important effect on postoperative vomiting in children after myringotomy. We studied 320 healthy children of ages 0.5-13 yr undergoing elective myringotomy and tube insertion. Induction and maintenance of anaesthesia were randomized to inhalation with either 70% N2O/30% O2/halothane or 100%O2/halothane. Surgical technique and postoperative management were not influenced by this study. Vomiting in the recovery room (PAR) and Day Care Surgical Unit (DCSU) was recorded by nurses unaware of the anaesthetic technique. Parents were contacted 24-48 hr after surgery to ascertain the incidence of vomiting after discharge. The groups were similar with respect to demographic data, except that the anaesthesia time was greater among the 158 patients in the N2O-treated group (11 +/- 4 vs 12 +/- 4 min, mean +/- SD). The incidence of vomiting was 13% in both groups. Most of the 42 patients that had emesis only vomited once or twice. The incidence of vomiting was not altered by sex (13% vs 13%) or duration of anaesthesia. The incidence of vomiting increased with increasing age. The children aged less than 3 yr vomited 4% of the time, those aged 3-5 vomited 11% of the time, those aged 6-8 yr vomited 17% of the time, while the incidence of vomiting among those aged 9-13 yr was 31%. Vomiting prolonged the postoperative hospital stay from 75 to 92 min, P < 0.001, ANOVA. In summary, we have been unable to demonstrate that N2O induces vomiting by children after a brief general anaesthetic for myringotomy.

Midazolam reduces vomiting after tonsillectomy in children

The purpose of this study was to assess the effect of midazolam on vomiting after tonsillectomy in children. We compared 215 children aged 1.5-14 yr undergoing tonsillectomy or adenotonsillectomy under general anaesthesia with nitrous oxide and halothane. In a double-blind fashion the subjects were administered either placebo or midazolam 75 micrograms.kg-1 iv after induction of anaesthesia. After the operation, the number of emetic episodes and the length of stay in hospital were recorded. The groups were similar with respect to age, weight, sex, mode of induction, duration of anaesthesia, surgical procedure, opioid administration and length of stay in the PAR and the Day Care Surgical Unit. The 108 midazolam-treated children had a lower incidence (42% vs 57%) of vomiting than the placebo group, P < 0.02. The placebo group had a higher incidence (9% vs 2%) of unscheduled admissions to hospital due to nausea and vomiting, P < 0.05. It is concluded that midazolam administered intravenously to children intraoperatively reduces vomiting after tonsillectomy.

Postoperative sore throat in children and the laryngeal mask airway

Postoperative sore throat is a minor complaint after general anaesthesia of multifactorial aetiology. The purpose of this study was to compare the effect of the laryngeal mask airway (LMA) and endotracheal tube (ETT) on postoperative sore throat in children. We hypothesized that the incidence of sore throat would be less after the use of the LMA. This was a randomized, single-blind study of 112 patients of age 3 to 12 yr undergoing minor peripheral surgery. The groups were similar, except that airway maintenance was either with an LMA or ETT. After induction of anaesthesia with O2, N2O and halothane, an LMA or ETT was inserted. Anaesthesia was maintained with O2, N2O and halothane. At the end of surgery, the ETT was removed in the operating room before airway reflexes had returned. The LMA was removed after the patient's airway reflexes had returned in the recovery room. On the first postoperative day, the parents were contacted and asked whether or not their child had had a sore throat. If a sore throat had been present, the parents rated the discomfort as mild, moderate or severe. The groups were similar with respect to age, weight, sex and duration of procedure. The overall incidence of sore throat was 9%. The difference between the groups (LMA 13% vs ETT 5%) was not statistically significant. All of the reported sore throats were rated as mild. In conclusion, postoperative sore throats after minor paediatric surgery is uncommon. If it does occur, it is mild and the incidence is unaffected by the choice of an LMA or ETT.

The mucopolysaccharidoses and anaesthesia: a report of clinical experience

Patients with the mucopolysaccharidoses show widespread, progressive involvement and derangement of many organs and tissues which can have profound implications for the anaesthetist. These disorders are uncommon and few anaesthetists care for these patients on a regular basis although individual patients often undergo multiple anaesthetics for procedures intended to improve their quality of life. There is a relative paucity of literature dealing with clinical anaesthetic experience with these patients. We report a retrospective review of the recent experience at the Children's Hospital of Eastern Ontario in Ottawa, Canada, administering 38 anaesthetics to nine patients with several of the mucopolysaccharidoses; specifically the Hunter, Hurler, Sanfilippo and Morquio syndromes. The establishment and maintenance of an adequate airway represents the most commonly encountered anaesthetic-related problem in these patients. We found an overall incidence of airway-related problems of 26 per cent. In patients with the Hurler or Hunter syndromes the incidence of airway-related problems was 53 per cent.